High Elevation - Is 87 octane still necessary?

I live in Colorado, where "regular" gas is 85 octane because of the elevation. I've still been filling up with 87, since that's what the owner's manual recommends, but I'm wondering if I'm wasting money spending 20 to 30 additional cents per gallon. Anyone who lives in a high elevation find that their Mirage runs just fine on 85 octane? I have a 2015 DE.

I live in Colorado, where "regular" gas is 85 octane because of the elevation. I've still been filling up with 87, since that's what the owner's manual recommends, but I'm wondering if I'm wasting money spending 20 to 30 additional cents per gallon. Anyone who lives in a high elevation find that their Mirage runs just fine on 85 octane? I have a 2015 DE.

I just drove the I70 from Utah and ran 85 through 3-12500' mountain passes and didn't have a single issue.